Cystic fibrosis (CF) is a life threatening genetic disease
affecting most critically the lungs, and also the pancreas, liver,
and intestine. It is characterized by abnormal transport of
chloride and sodium ions across the epithelium, leading to thick,
viscous secretions in the airways. CF results from the
homozygous recessive condition, afflicting one out of every 2,500
babies in the Caucasian population of the United States. .
Utilizing the Hardy-Weinburg principle…..
Calculate the genotypic frequency for the homozygous recessive
condition, in the U.S. Caucasian children.
Calculate the genotypic frequency for the homozygous dominant
healthy condition, in the U.S. Caucasian children.
What is the % frequency of heterozygous carriers in U.S.
Bepari, Paul, Malakar, and Chakraborty analyzed 29 countries for
the prevalence of the cystic fibrosis allele For each of the
following countries, calculate the probability of a child being
born with cystic fibrosis:
i.Switzerland has the highest gene
frequency ( 0.022 gene frequency for the CF allele)
ii.Japan has the lowest gene frequency
(0.002 gene frequency for CF)
In comparison to Caucasians, the frequency of CF heterozygous
carriers is lower for minority groups, including Hispanics (1 in
46), African Americans (1 in 60) and Asians (1 in 150). Experiments
have shown that CF carriers have saltier sweat than people with two
normal alleles. From an evolutionary standpoint, speculate why the
salty sweat characteristic may explain the differences in CF
heterozygous frequencies among different minority groups in the
A college enrolls approximately 3,000 students, of which 6.4%
are Hispanic/Latino, 3.9% are Black or African American, and 0.5%
are Asian. (Another 10.5% are unspecified or two or more races,
2.2% are non-resident aliens, 1.3% are American Indian or Alaska
native. As we cannot speculate on the allele frequency of these
groups, assume that their CF allele frequency mirrors that of the
general U.S. Caucasian population.) Assuming that the CSC
population reflects this general frequency of the CF allele
frequency, approximately how many college students may have the
heterozygous phenotype (i.e., would be carriers)?